1. Field of the Invention
The present invention relates to a high frequency heating apparatus for heating a material to be heated such as food in which the temperature of the material to be heated is detected to efficiently heat the material to be heated, make a heating distribution uniform and automate a cooking.
2. Description of the Related Art
As such a heating and cooking apparatus, a cooking and heating apparatus has been hitherto disclosed in, for is example, JP-A-2001-250672. FIG. 7 shows the conventional heating and cooking apparatus described in the above-described publication.
In FIG. 7, in a microwave range, a bottom plate 1 forms a bottom surface of a heating chamber 2. Microwave oscillated by a magnetron 3 is supplied to a wide area in the heating chamber 2 by a rotary antenna 4. In the microwave range, a method for heating the food in the heating chamber 2 is different depending on a rotating position where the rotary antenna 4 is stopped or a position where the food is mounted on the bottom plate 1. In the right side surface of the heating chamber 2, a hole 5 is formed. One end of a detection path 6 is connected to the hole 5 of the heating chamber 2. Then, to the other end of the detection path 6, an infrared sensor 7 is attached. The infrared ray sensor 7 has a visual field in the heating chamber 2 and can detect an amount of infrared ray radiated in the visual field. That is, the infrared ray sensor can detect temperature in the visual field. Then, when the magnetron 3 oscillates microwave, the rotary antenna 4 is rotated to and stopped at a rotating position where the food is most efficiently heated at a determined position where the food is mounted.
In the conventional structure, as shown in FIG. 8, the hole 5 is formed in the right side surface of the heating chamber 2 and the infrared ray sensor 7 detects the temperature in the visual field through the detection path 6. When two foods 8 and 9 of different size are heated, if the larger food 8 is placed near the infrared ray sensor 7, infrared rays radiated by the smaller food 9 are interrupted by the food 8. Thus, the infrared rays may not possibly reach the infrared ray sensor 7 so that the temperature of the food 9 cannot be detected to overheat the staller food. Accordingly, when such foods having different size are heated, unless the smaller food is placed in the right side or the two foods are placed in the direction of length of the heating chamber 2, the temperature of the two foods cannot be detected. Therefore, a user needs to consider positions where the foods are to be placed depending on the size of the foods or a user needs to extend a hand to an interior of the heating chamber 2 and place the foods. Accordingly, maneuverability is not inconveniently good.